Synergistic insecticidal compositions



States- Unite SYNERGISTIC INSECTICIDAL COB POSITIONS No Drawing. Original application Mar. 24, 1955, Ser.'

No. 496,596. Divided and this application Oct. 17, 1958, Ser. No. 767,781

5 Claims. (21. 167-22) This invention relates broadly to insecticidal compositions, and more particularly toinsecticidal compositions.

containing an organic carbamate acid derivative and 0,0-dimethyl S-(1,2 dicarbethoxyethyl) dithiophosphate, hereinafter referred to as Malathion. More particularly, this invention relates to synergistic insecticidal compositions of these compounds wherein the insecticidal effectiveness of each component is enhanced by the presence of the other to produce an unexpected combined effect.

When two or more substances in combination show an unexpectedly higlractivity, as, for instance, insecticidal activity, the resulting phenomenon is called synergism. The mechanism of synergism is by no means understood. It is, in fact, quite probable that it differs with diflerent synergistic combinations. The term synergism can be defined, however, as a cooperative action which is encountered in combinations of twoor more biologically active components in which the combined activity of the two components exceeds the sum of the activities of the components when used alone. The insecticidal activity of the mixed components cannot be predicted from known values of the individual components, but is unpredictable and depends on the individual activity of neither.

It is an object of this invention to provide insecticidal compositions of enhanced killing power. Another object of this invention is to produce novel compositions containing compounds capable of synergizing the. knockdown and killing properties of individual toxicants. A further objectof this invention is to provide compositions including a relatively toxic phosphorous containing insecticide in which superior insecticidal activity is obtained because of the synergistic effects, but in which'the ultimate toxicity to warm-blooded animals is greatly reduced because of the lower concentrations of the phosphorous compounds required when used in combination with the relatively less toxic carbamates. vantages of the invention will become apparent from the description of the invention set forth below.

According to this invention there are provided synergistic insecticidal compositions comprising 0,0-dimethyl S-(l,2 dicarbethoxyethyl) dithiophosphate and an organic carbamate ester of the following general formula NCOOR wherein R is ethyl and R is selected from the group consisting of 3-methylphenyl, 4-methylphenyl and 3-5- dimethylphenyl. These carbamates may be prepared as described in copending application Serial No. 812,113, filed May 11, 1959.

The synergistic insecticidal compositions of this invention may be used on a wide variety of insect and mite species, but are particularly effective against the twospotted spider mite. The combinations are highly effective and economical to use for such large-scale insecti- Other objects and adatent 0 ice ition of insects, mites and the like.

2,955,069 Patented Get. 4, 1960 cidal requirements as the control of truck crop, forage crop and orchard insects.

The synergistic compositions of this invention can be formulated as aqueous emulsions, as dry or wettable powders, as solutions or in any other suitable vehicle. The insecticidal compositions can be utilized as sprays, as dusts, as aerosol mixtures, insecticidal coating compositions, and as residues. In general, they can be applied by methods commonly used for control or eradica- Thus these insecticidal compositions can be formulated with solvents, di-

luents and carrier media, adhesives, spreading, wetting an emulsifying agents and other ingredients.

The relative proportions of the active ingredients as for the Malathion and from 0.10% to 25.00% for the carbamate.

The procedures of the testing method are described below. The details of the test experiments including the type of formulation and mode of application or dosing, and the species of insects which served as test subjects are given in the examples.

The test method used is described as follows:

DUST TOWER METHOD This general method is described in the following reference, Moore,-J. Econ..Ent. 43,-No. 2, 188-190 (1950). The dusting apparatus consists of a vertical glass cylinder, 34 inches high and.8.5 inches in diameter, into which the appropriate dust sample is discharged through a small hole in the center of the cover, by means of a small laboratory duster operating at an air pressure of 40 p.s.i.g. The duster assembly comprises a 10 ml. beaker, into which the weighed sample is placed, and fitted with a rubber stopper through which pass the air inlet and dust outlet tubes, both of which are made of inch diameter copper tubing. At the outer end of the air inlet tube is a trigger valve that servesas a control for dispensing the dust. The inner end of this tube reaches nearly to the bottom of the beaker. The end of it is sealed but, along the sides, seven 0.032 inch holes are drilled at irregular intervals which serve as air inlets. Such an arrangement causes pronounced turbulence of the dust and thus insures exhausting the complete sample from the beaker. The dust outlet tube forms an arch from the top of the beaker to the top of the glass dusting tower.

After the discharge of the sample into the tower, there is allowed a 2-minute settling time before removal of foliage or insects being treated. A weighed metal plate V 3 bean plants by a talnglefoot ring. The bean plants were placed in the glass tower and the mites direct- V dusted. Mortality readings were taken in 24 hours. Only adult mites were used in determining mortality 4. Synergistic insecticidal compositions comprising 0, O-dimethyl S-(l,2 dicarbethoxyethyl) dithiophosphate and 3-5 dimethylphenyl N-et hylcarbamate, said components being present in the ratio of about 2 parts of said mate ester per part-of said dithiophosphate.

counts; 5 carbamate ester per part of said dithiophosphate.

Table 1 i R4 a V V NCOOB Qarbarnate V V Phosphate R t .i (1335/ Test Method Test Subject -Mortality Dust Dust acre) w r (Percent) R R9 Cone. Name Cone.

(Percent) (Percent) ethyl i-methylphenyl 1 9.4 Dust Tower lilvg tspottedp'ider l -j-i r Malathiomto 0.5 9.3 88 ethyl 4-rnethylphenyl 1 o 0.5 5.7 100 Do 3-n1ethylphenyl .4. 0.5 11.2 0 Malathiom--. 0.25 10.4 ethyl 3-methylphenyl v V 0.5 0.25 10.4 99 D01 3-5-dimethylphenyl- 0.5 10.5 4 a 0.25 12.6 66 ethyl 3-5-dimethy1phenyl 0.5 0.25 11.2 100 This table demonstrates the unexpected effectiveness 5. The method of killing insects which comprises apof the insecticidal compositions of this invention against plying to the insects and their habitat a synergistic inthe two-spotted spider mite. sectic-idal composition comprising O,Q-dimethyl S(1,2 This application is a division of co-pending application dicarb'ethoxyethyl) dithiophosp ha'te and an organic car- Serial No. 496,596, filed March 24, 1955, now abandoned, bamate having the general formula which is a continuation-in-partof Serial No. 427,374, filed May 3, 1954, now abandoned. Thatwhich is claimed as patentably novel is: NCOORP 1'. Synergistic insecticidal compositions comprising 0, H Q-dimethyl S-(1,2 dicarbethoxyethyl) dithiophospliate p v V and an organic carbamate ester of the following general wherein R is ethyl and R is vselected from the group formula consisting of 3-methylphenyl, 4-methylphenyl and 3,5-di- R1 methylphenyl radicals, wherein'said components are pres- V entrinthe ratio of about 2 parts of said carbarnate per 40 part of said dithiophosphate wherein R is ethyl ancl R is selected from the group Refer-ewes (Med 111 of Patent consisting of 3-methylphenyl, 4-methylphenyl and 3-5-di- UNITED STATES PATENTS methylphenyl, wherein said components are present in the 2 503 390 Jen-113k f 1 .7 A 5 ratio of about 2 parts of said carbam ate per part of said .45 V 1 -3 Gysin V 3 5 4 dlthlOPhOSphfltB. V V V V .7 -s a 7 2. Synergistic insecticidal'compositions comprising 0; O E R R NC o dimethyl S-(1,2 dicarbethoxyethyl) dithiophosphate v V V V a and 3-methylphenyl N ethylcai'bamate, said components pp fg Dept Handbook i h 9 P 2 Parts of said Chemical Age, vol. 63, No; 1631 1950, p. 540. bamate-ester per part of said dithlophosphate. t s A t, N L J F b v 1952 3. Synergistic insecticidal compositions comprising 0, 1 2 ews s wary 'O-dimethyl S-(1,2 dicarbethoxyethyl) tdithiophos'phate a V l and 4-methylphenyl N-ethylcarbamate, said components lg'g i l? 5 33: $3 5 1955 being present in the ratio of about 2 parts of said carba- 0 t e estm an-uary 

1. SYNERGISTIC INSECTICIDAL COMPOSITIONS COMPRISING O, O-DIMETHYL S-(1,2 DICARBETHOXYETHYL) DITHIOPHOSPHATE AND AN ORGANIC CARBAMATE ESTER OF THE FOLLOWING GENERAL FORMULA 